The present invention relates to a milling cutter, and more particularly to a cartridge-type milling cutter composed of a disc-shaped cutter body and a plurality of cartridges each having a plurality of cutting edges on an outer peripheral surface thereof and attached successively to the outer peripheral surface of the cutter body, the cutting edges of the cartridges being spaced at substantially equal intervals.
Milling machines widely used in the art have a circular milling cutter fitted over a shaft for cutting a workpiece as it is fed at a predetermined speed. Conventional milling cutters can roughly be grouped into two types: In one type, the cutter body and the cutting edges are integral with each other, and according to the other type, the cutter body and the cutting edges are separate from each other. The milling cutter of the former class is disadvantageous in that when the cutting edges are worn by milling a large number of workpieces, the entire milling cutter must be replaced even if only the cutting edges are required to be replaced. For milling different types of workpieces, different milling cutters must be used. Therefore, as many milling cutters as the number of different workpiece types to be milled should be kept in stock.
As disclosed in U.S. Pat. No. 3,701,187, the milling cutter of the latter type has a plurality of tips detachably attached to the cutter body, and only those tips which have been worn can be replaced.
However, there is a limitation on the number of tips that can be fixed to a single cutter body, and quite a large space is required for attachment of the tips. Consequently, the number of tips which can be fastened to the cutter body is not so great. When the tips are to be changed to mill a particular workpiece to be milled, the bolts by which the tips are fastened to the cutter body must be loosened one by one to remove the tips. Such a procedure is so tedious and time-consuing that it is practically infeasible in factories and machine shops. For milling a workpieces to produce rough and and then finished surfaces, two milling cutters have to be used. After the workpiece has been milled by the rough milling cutter, the rough milling cutter should be replaced with the finishing milling cutter. The replacement process is highly complex and time-consuming, resulting in a low rate of production. Generally, the number of finishing tips or flat drags is one or two, and hence the milling efficiency is poor.